Zero-downtime Redis upgrade discussion. GitHub have a short window of scheduled downtime in order to upgrade their Redis server. I asked in their comments if they’d considered trying to run the upgrade with no downtime at all using Redis replication, and Ryan Tomayko has posted some interesting replies. #28th May 2010, 2:50 pm

Round-robin Django setup with nginx. An nginx trick I didn’t know: a low proxy_connect_timeout value (e.g. 2 seconds) combined with the proxy_next_upstream setting means that if one of your backends breaks a user won’t even see an error, they’ll just have a short delay before getting a response from a working server. #21st December 2009, 3:43 pm

I loathe [hardware load balancers]. They’re expensive, restrictive, slow, and generally cause you a lot more pain and suffering than they’re worth. At my last job, one of my projects was to convert most of one of our existing clusters from a load-balancing appliance to use keepalived. Why would we do this? Because the $100k worth of appliance wasn’t capable of doing the job that $15k worth of commodity hardware and an installation of keepalived were handling with ease.

We’re all ops people now. Edd’s experience reflects my own: the kind of systems I’m building these days involve way more than just development, they often involve significant sysadmin type skills as well. Desperately need to get better at that stuff. #20th June 2008, 9:02 pm